Power control



Feb. 13, 1940.

M. J. KITTLER POWER CONTROL Filed Aug. 17, 1958 INVENTOR Nu. TON d. K1? 7/. ff?- BY ATTORNEY g9 known design;

Patented Feb. 13,1940

ENT oFF cE POWER cosmos Milton J. Kittler, Detroit, .Mich.,- assignor to George M. Holley and Earl Holley Applicatin-August l7, 1938,, Serial No. 225,39

The, object of this invention is to enable an airplane engine to maintain its power either uniform or at a slight loss as the engine climbs.

If the pressure of the supercharger is maintainedconstant, there is inevitably a large increase of power as the plane ascendsv and the increase of power at 30,000 feet wouldbe of the order of thirty per cent; It follows, therefore, that a constant supercharger pressure is not,.a

n complete solution. The maximum pressure at the air entrance at the. inlet valves of the engine should constantly diminish as the altitude increases in order that the engineshould develop its maximum power on. the ground and should l5 never exceed this maximum in the air at any altitude. i

The figure shows diagrammatically the preferred form of my invention.

In the figure, ii] is a Vacuum pump of well H is a vacuum cylinder in which there reciprocates a piston lZconnected-through a rod IS with a piston 14' which reciprocates in the pressure cylinder 15, which communicates through the pipe 6 with the pressure side of 25 the supercharger l1.

The details of the carburetor construction are omitted, and in the air entrance leading to the supercharger ll is simply shown the throttle valve is located inan air passage. This throttle 3 I8 is controlled. by a-lever it connected through a link 26, to a lever 2| rotatably mounted. in the casting containing the cylinders, H and I5. This lever 21 extends upwards and engages through a slotted opening 22 with a pin .23

, projecting laterally from the rod l3. 0 The oscillating lever 2! extends up to engage with the link 24- which has a one-Way connection with a tu'be'iiti. This one-way connection is normally caused to act as a two-way connection by means of a spring 25, which seats .against a Washer located on the link 24. A pin 28 on the right hand end of thetubular piece 25 is engaged by the manual lever 29 pivoted at 30 on. the casting which carries the cylinders H and i5. A handle 3! is shown to control the movement of the throttle IB.

An adjustable spring 32 adjusted by a threaded spring support 33 is used to maintain the system in equilibrium.

Operation When the engine is in operation, a constant pressure of say one pound absolute per square inch is maintained in the cylinder II. Atmospheric pressure acts on the piston l2. Hence the tendency is as the atmospheric pressure the 8 Claims; (01. 123-75) decreases for the pressure on the piston l2 to. V

decrease, which permits the rod I 3 to move, to the right and thus permits the oscillating lever 25 to move in a clockwise direction to open throttle ill to maintain the power constant ii altitude 'i'allsq When the levers ill and 3| aremovedin a counter-clockwisedirection and the spring 26 is compressed, the throttle is closed. The net result is to overcome the effect of the spring 32 and thus reduce power.. Meanwhile, 9 the supercharger pressure is acting on the piston it which, it will be noticed, is slightly larger than the vacuum piston I2. The tendency of an increase in supercharger pressure isfto'also move the oscillating lever 2| inra counterclockwise direction, that is to say, to close the throttle.

At every position of the hand lever 3i equilibrium will be reached when thefollowing forces are in balancethe superchargerpressure acting on the piston M, the atmospheric pressu're acting on the difierence inarea between the pistons l2 and i and the compression of the spring 2.? acting against the spring 32; There will, therefore, be a tendency for the throttle to open as the plane rises in altitude, because as the engine rises, there will be a tendency for the atmospheric pressure acting on the piston ill to fall and there will also be a tendency. for the supercharger acting on the piston 14 to fall. The decrease of both of these causes a clockwise movement of the oscillating lever 2|, and therefore anqopening movement of the throttle l8.

. As the piston H is slightly larger than the piston l2, an increase in atmospheric pressure (decrease in altitude) has a tendency to cause the throttle to open. This opposes the tendency of a constant supercharger pressure to increase the power as altitude increases. If the throttle 40 is in the position shown, we will assume that it permits the engine to develop its rated-power on the ground at sea level. Then, as the plane rises, the throttle will open automatically under the influence of the spring 32 to maintain the supercharger pressure in l5 at the figure determined by the adjustable spring support 33. As the piston M is larger than the piston l2 by a slight amount, the corresponding decrease in atmospheric pressure acts as a force acting on the left and therefore, weakens the spring 32,

or it rather opposes the spring 32 so that there is a tendency for the decreased atmospheric pressure to close the throttle which is the desired result. By this means, the engine will inch. Assuming that the supercharger pressure is at say 16 pounds per square inch; then we get air and mixture flowing into the cylinder under a pressure differential of nine pounds per Thus, the charge is much greater square inch.

than it is at sea level and this is the major cause of the increase of power 'if the superi charger power is maintained constant. This increase is of the order of one per cent per 1000 feet.

Obviously, instead of locating the-vacuum cylinder H and the pressure cylinder 15 on the same axis, the pressure cylinder 15 may be made of the same diameter as the vacuum cylinder it and located so as to have a greater mechanical advantage. which, of course. is the full equivalent of making the pressure cylinder larger and locating it on the same diameter as the chamber of the vacuum cylinder.

An arcuate projection 34 engages in an arcuate guideaf to hold the manual control 3! in any given position. In long flights the throttle control is positively locked in some given position, but the locking means are not shown in this drawing. I I

Attention is drawn to the fact that the throttle Eli canbe positively opened and positively closed by the throttle'control lever 3|. In other words, the control of the throttle can be taken completely away from the automatic control. This is because the compression spring 26 is adapted to collapse on itself when it acts as a solid connection between the lever 2i and the link 25.

What I claim is:

1. In a throttle controlled supercharged engine, a throttle lever, a manually operated link having a positive one-way connection adapted to positively open the throttle, a loose connection and a spring associated therewith permitting the throttle to be yieldingly closed, 'a second spring adapted to open the throttle, means responsive to 1 the pressure of the superchargeralso connected to said throttle lever and adapted to open the throttle until the pressure of the supercharger above the atmospheric pressure equals the pressure determined by the second spring.

2. A device as set forth in claim 1 in which adjustable means are provided for adjusting the effect of said second spring.

3. A device as set forth in claim 1 in which means are provided responsive to a decrease in atmospheric pressure to permit a lower supercharger pressure to be maintained at low atmospheric pressure.

4. In a throttle controlled supercharged engine, a throttle lever, a source of vacuum, a vacuum cylinder, a piston therein, spring means connected with said lever so as to oppose the action of the vacuum, means for admitting atmospheric pressure to the other side of the piston, a second cylinder, a piston therein subjected on one side to the pressure in the supercharger, means for admitting atmospheric pressure to the other side of the piston, means for connecting both pistons to the throttle lever so that the vacuum means and the supercharger pressure means act in the same direction, manual means for moving the throttle lever to an open position, a yielding connection between said manual control means and said throttle lever, the piston responsive to the action of the supercharger pressure being adapted to close the throttle when the supercharger pressure exceeds a figure determined by the spring whereby the pressure in the supercharger is automatically maintained at a figure determined by the spring. A device as forth in claim 4 in which the diameter of the piston responsive to supercharger pressure is slightly greater than that of the piston responsive to the vacuum and both pistons are located on the same centerline.

6. A' device as set forth in claim 4 in which the leverage exerted by the piston responsive to the supercharger pressure is slightly greater than the corresponding leverage exerted by the vacuum responsive piston.

7. A device as set forth in claim 4 in which the yielding connection between the manual control means and the throttle lever comprises a second spring adapted to oppose the first mentioned spring when the manual control is moved to its closed position so that the pressure in the supercharger is maintained at a lower figure when the manual control is moved away from the wide open towards the closed throttle position.

8. A device as set forth in claim l in which the yielding connection between the manual con- 

